Dewaxing petroleum oils



Patented Oct. 4, 1938 PATENT OFFICE D'EWAXING PETROLEUM OILS Eugene C. Herthel, Flossmoor, IlL, assignor'to Sinclair Refining Company, New York, N. Y., a

corporation of Maine No Drawing. Application July 5, 1934,- Serial No. 733,857

9 Claims.

This invention relates to improvements in the dewaxing of hydrocarbon oils, more particularly to the dewaxing of petroleum stocks in the manufacture of lubricating oils. The invention relates particularly to improvements in the diluents described in an application of Edward J. Martin filed February 21, 1934, Serial Number 712,412. The invention is also useful in connection with the diluents described in my application filed July 5, 1934, Serial Number 733,858 now Patent 2,056,723.

The diluents described in application Serial Number 712,412 comprise the ethyl esters and mixtures of ethyl esters higher boiling than acetic ethyl ester including the valeric ethyl esters, propionic ethyl esters and butyric ethyl esters, and ethyl esters and mixtures of ethyl esters boiling within the range 185-315 F.

In accordance with this invention, these high boiling ethyl ester diluents are used in conjunction with hydrocarbon diluents, of boiling range lower than that of the oil to be dewaxed, such as benzol, mixtures of benzol and toluol, mixtures of benzol and petroleum naphtha and mixtures of toluol and petroleum naphtha for example. If, in the absence of propionic ethyl ester, the proportion of ethyl esters higher boiling than propionic ethyl ester is limited to about 25% of the composite diluent as a minimum, or if the proportion of ethyl esters higher boiling than propionic ethyl ester is limited to about 7.5% of the composite diluent as a minimum, propionic ethyl ester being present in proportion limited to about 17.5% of the composite diluent as a minimum, a given volume of the composite diluent is usually about as effective as the same volume of the high boiling ethyl esters.

The invention is similarly useful in conjunction with the high boiling alkyl ester diluents, other than the high boiling ethyl ester diluents, including normal butyl valerate, isopropyl Valerate, normal propyl valerate, and secondary butyl valerate, normal butyl butyrate, normal butyl caproate, normal butyl propionate, iso butyl butyrate, iso butyl iso butyrate, iso butyl propionate, iso butyl valerate, propyl butyrate, propyl iso butyrate, propyl propionate and propyl iso valerate, described in application Serial Number 733,858.

Since these high boiling esters are more costly than the hydrocarbon diluent component of the composite diluent of this invention, this invention makes possible important economies with respect to the cost of the total volume of diluent required to carry out any particular dewaxing operation without necessarily involving prejudice to the eificiency of the dewaxing operation and without necessarily involving sacrifice of the advantages of the high boiling ester diluents.

The following examples of operations embodying the use of composite diluents of this invention will further illustrate the invention:

Example 1.A Mid-Continent overhead long residuum having a viscosity of 120 seconds at 210 F. is diluted with 300% of its own Volume of a composite diluent consisting of 1 part (by volume) of a mixture of ethyl esters boiling within the range 185315 F. and including about (by volume) of propionic ethyl ester, the balance being principally iso valeric ethyl ester, and 3 parts of benzol, the mixture is chilled to 14 F., about 16.4% of precipitated wax having a melting point of about 126 F. is separated from the fluid stock mixture by filtration, and the composite diluent is steam distilled from the fluid stock mixture to produce a dewaxed oil having a pour test of 4 F.

Example 2. A Mid-Continent overhead long residuum having a viscosity of seconds at 210 F. is diluted with 300% of its own volume of a composite diluent consisting of 1 part (by volume) of a mixture of ethyl esters boiling within the range -315 F. and including about residuum having a viscosity of 120 seconds at 210 F. is diluted with 300% of its own volume of a composite diluent consisting of 1 part (by volume) of a mixture of ethyl esters boiling Within the range 185315 F. and including about 70% (by volume) of propionic ethyl ester, the balance being principally iso valeric ethyl ester, and 3 parts of a blend of 50% toluol and 50% petroleum naphtha, the mixture is chilled to 14 F., about 5.6% of precipitated wax having a melting point of about 143 F. is separated from the fluid stock mixture by filtration, and the composite diluent is steam distilled from the fluid stock mixture to produce a dewaxed oil having a pour test of 16 F.

Example 4-.A Mid-Continent overhead long volume) of propionic ethyl ester, the balance be- 106 F. is separated from'the fiuid stock mixture by filtration, and the composite diluent is steam' the range 185-315 F. and including about (by volume) of propionic ethyl ester, the balance being principally iso valeric ethyl ester, and 3 parts of a blend of 50% benzol and 5 0% petroleum naphtha, the mixture is chilled to--15 F., about 11.0% of precipitated wax having a melt; ing point of about 126 F. is separated from the" Example '5.A Mid-Continent paraffin distil- 1 late having a viscosity of 87 secondsat 100 F. is diluted with 300% or" its own volume of a composite diluent consisting of 1 part (by volume) of a mixture of ethyl esters higher boiling than propionic ethyl ester and consisting essentially of iso Valerie ethyl, ester, and 3 parts of a blend of 50% benzol and 50% petroleum naphtha, the mixture is clilied to -15 about 9.9% of precipitated wax having a melting point of about 117.5 F. is separated from the fluid stock mixture of filtration, and the composite diluent is steam distilled from thefiuid stock mixture to produce a dewaxed oil having a pour test of 16 F.

Example 6.-A Mid-Continent paramn distillate having a viscosity of 87 seconds at 100 F. is diluted with 300% of its own volume of a composite diluent consisting of 1 part (by volume) of a mixture of ethyl esters boiling within the range 185-15 F. and including about 70% (by ing principally iso valeric ethyl ester, and 3 parts of a blend of 20% acetone and 80% benzol, the mixture is chilled to' 10 F., about 16. 2% of precipitated wax having a melting point of about distilled from the fluid stool: mixture to produce a dewaxed oil having a pour test of 2 F.

Escample 7.A Mid-Continent'parafiln distillate having a viscosity of 87 seconds at 100 F. is diluted with-300% of its own volume of 'a com-v posite diluent consisting of 1 part (by volume) of a mixture of ethyl esters boiling within the range 185-315 F. and including about 70% (by volume) of prop-ionic ethyl ester, the balance being principally iso valeric ethyl. ester, and 3 parts of a blend 7 of 50% benzol and 50% petroleum naphtha, the mixture is chilled to 10 F.,,about 16.2% of precipitated wax having a melting point of about 109 F.'is separated from the fluid stock mixture by filtration and the composite diluent is steam distilled from the fiuid stock mixture to produce a dewaxed oil having a pour test of 4 F.

Example 8.-A Mid-Continent paraffin distillate having a viscosity of 87 seconds at 100 F. is diluted with 300% of its own volume of a composite diluent consisting of 1 part (by volume) of a mixture of ethyl esters boiling within the range '185-315 F. and including about 70% (by volume) of propionic ethyl ester, the balance being principally iso valeric ethyl ester, and 3 partsof a blend of 20% toluol and benzol, the mix ture is chilled to l0 F., about 12.2% of preciptilled from the fluid stock mixture to produce a dewaxed oil having a pour test of 10 F.

Example 9.A' Mid-Continent paraffin distillate having a viscosity of 87 seconds at F. is diluted with 300% of its own volume of a composite diluent consisting of 1 part (by volume) of a mixture of ethyl esters'boiling within the range 185-3l5 F. and including about 70% (by volume) of propionic ethyl ester, the balance being principally iso valeric'ethyl ester, and 1 part of a blend of 35% acetone, 52% benZo-l and 13% toluol, the mixture is chilled to 10 F., about 14.8% of precipitated wax having a melting point of about 110 F. is separated from the fluid stock mixture by filtration and the composite diluent is.

steam distilled from the fluid stoclsniixture to produce a dewaxed oil having a pour test of 4 F.

Example 10.-A Mid-Continent overhead long residuum having a viscosity of seconds at 210 'F. is diluted with 300% of its own volume of a composite diluent consisting of 1 part (by volume) of a mixture of ethyl esters boiling 'within the range -315 F. and including about 7 0% (by volume) of propionic ethyl ester, the balance being principally iso valeric ethyl ester, and 3 parts of a blend of 50% benzol and 50% petroleum naphtha, the mixture is chilled to 20 F.,

a about 7.15% of precipitated wax having a melting point of about 137 F. is separated from the fluid stock mixture by filtration, and the composite diluent is steam distilled from the fiuid stock mixture to produce a dewaxed oil having a pour test of 4 F. This dewaxed oil is treated with 30 pounds per barrel of 66 Be. sulfuric acid and thereafter with 25% (by weight) of fullers earth (Olmstead) at500 F., as in conventional practice, to produce a treated, dewaxed oil having a pour test of 0 F. Y

Example 11.-A Mid-Continentoverhead long residuum having a viscosity of 120 secondsat 210 F. is diluted with 300% of its own volume of a composite diluent consisting of l-part (by volume) of a mixture of ethyl esters boiling within the range 185315 F. and including about 70% (by volume) of propionic ethyl ester, the balance being principally iso valeric ethyl ester, and '3'parts of a blend of 25% toluol and 7.5% benzol, the mixture is chilled to =20 F.,'

r the fiuid stock mixture by filtration, and the composite diluent is steam distilled from the fluid stock mixture to produce a dewaxed oil having a pour test of 4 F. This dewaxed voil is treated with 30 pounds per barrel of 66 Be. sulphuric acid and thereafter with 25% (by weight) of'iullers earth (Olmstead) at 500 F., as in conventional practice, to produce a treated .dewaxed oil having a pour test of 0 F.

As used herein, the term pour test'is the lowest temperature at which the oil will; flow when chilled without disturbance, determined,

viscosities herein are viscosities in Saybo1t'Uni-- versal.

I claim:-

1. In the dewaxing of petroleum oils, the im.

provement which comprises diluting the oil with a composite diluent comprising 'a high boiling alkyl ester boiling within the range 185-3l5 F.,'

provement which comprises diluting the oil with 1 a composite diluent comprising an ethyl ester boiling within the range -3l5 F., said ester being miscible with the oil to be dewaXed, and a major proportion of a volatile hydrocarbon diluent of boiling range lower than that of the oil to be dewaxed.

3. In the dewaxing of petroleum oils, the improvement which comprises diluting the oil with a composite diluent comprising an ethyl ester higher boiling than propionic' ethyl ester, propionic ethyl ester and a major proportion of a volatile hydrocarbon diluent of boiling range lower than that of the oil to be dewaxed.

4. In the dewaxing of petroleum oils, the improvement which comprises diluting the oil with a composite diluent comprising a mixture of ethyl esters boiling within the range 185-315 F., said ester being miscible with the oil to be dewaxed, and a major proportion of a volatile hydrocarbon diluent of boiling range lower than that of the oil to be dewaxed.

5. In the dewaxing of petroleum oils, the improvement which comprises diluting the oil with a composite diluent comprising a mixture of ethyl esters higher boiling than propionic ethyl ester, propionic ethyl ester and a major proportion of a volatile hydrocarbon diluent of boiling range lower than that of the oil to be dewaxe'd.

6. In the dewaxing of petroleum oils, the improvement which comprises diluting the oil with a composite diluent comprising a Valerie alkyl ester and a major proportion of a volatile hydrocarbon diluent of boiling range lower than that of the oil to be dewaxed.

7. In the dewaxing of petroleum oils, the improvement which comprises diluting the oil with a composite diluent comprising a Valerie ethyl ester, propionic ethyl ester and a major'proportion of a volatile hydrocarbon diluent of boiling range lower than that of the oil to be dewaxed.

8. In the dewaxing of petroleum oils, the improvement which comprises diluting the oil with a composite diluent comprising a butyric alkyl ester and a major proportion of a hydrocarbon diluent of boiling range lower than that of the oil to be dewaxed.

9. In the dewaxing of petroleum oils, the improvement which comprises diluting the oil with a composite diluent comprising a propionic alkyl ester, said ester being miscible with the oil to be dewaxed, anda major proportion of a volatile hydrocarbon diluent of boiling range lower than that of the oil to be dewaxed.

EUGENE C. HERTHEL. 

